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DDT absorption and chylomicron transport in rat
Author(s) -
Pocock Dorothy M. E.,
Vost Alan
Publication year - 1974
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02532054
Subject(s) - chylomicron , triglyceride , chemistry , medicine , lymph , albumin , endocrinology , serum albumin , biochemistry , cholesterol , biology , lipoprotein , very low density lipoprotein , pathology
Male rats were fed 100 nM dichlorodiphenyltrichloroethane‐ 14 C in oil by gastric tube. Recovery of dichlorodiphenyltrichloroethane‐ 14 C in thoracic duct lymph was 60% in 12 hr. Lymph dichlorodiphenyltrichloroethane‐ 14 C (97%) occurred in lipoproteins of d<1.006, designated chylomicrons. Mechanical separation of chylomicron triglyceride core (labeled with triglyceride‐ 3 H) from chylomicron membrane (labeled with phospholipid‐ 32 P) showed that 97% dichlorodiphenyltrichloroethane‐ 14 C was present in triglyceride core. To investigate possible association of plasma clearance of the two core lipids, rats were pulse injected with chylomicrons, doubly labeled with triglyceride‐ 3 H and dichlorodiphenyltrichloroethane‐ 14 C. The decay of dichlorodiphenyltrichloroethane‐ 14 C in sequential serum samples was rapid (T 1/2 =2 min) and was independent of triglyceride‐ 3 H decay. In tissues removed 14 min after injection of chylomicrons, 30% administered dichlorodiphenyltrichloroethane‐ 14 C was found in liver but only 1% in adipose tissue. In hepatectomized (eviscerated) rats, the decay of serum dichlorodiphenyltrichloroethane‐ 14 C (T 1/2 =10 min) was also independent of and more rapid than triglyceride‐ 3 H decay. With sucrose density gradients, it was shown that chylomicron dichlorodiphenyltrichloroethane‐ 14 C transferred to higher density serum proteins in vitro and in vivo and to bovine albumin in vitro. Thus, dichlorodiphenyltrichloroethane was transported from intestine largely in the triglyderide phase of chylomicrons; disappearance of chylomicron‐dichlorodiphenyltrichloroethane from the systemic circulation was rapid and partly independent of the presence of the liver and of triglyceride hydrolysis; some dichlorodiphenyltrichloroethane was transported from serum chylomicrons to albumin or other plasma proteins before tissue uptake.